In order to analyze the growth pattern of tree height of planted Pinus koraiensis and screen the provenances with fastest growth, we grouped the provenances using the differences in tree height, diameter at breast height (DBH) and volume of timber of 234 individuals of planted P. koraiensis from 26 provenances in Maoershan Experimental Forest Farm. We constructed the growth equation for tree height by combining the base models of Gompertz, Korf, Richards, Logistic, and Schumacher, and then selected the optimal one. We introduced the prove-nance grouping as a dummy variable into the base model, and evaluated the optimal tree height growth equation by a comprehensive evaluation of the model according to the coefficient of determination (R²), the root-mean-square error (RMSE), the Akaikei Information Criterion (AIC), and the model's predictive precision (F_P). The results showed that the growth traits of the 26 provenances had significant difference among the groups, and that tree height and DBH showed significant differences among the provenances. According to the comprehensive consideration of different growth traits, the four groups of provenance growth were divided into group A (Wuying, Hebei, Linjiang, Dongfanghong, Huanan, Lushuihe, Fangzheng) >group B (Aihuisanzhan, Liangshui, Tieli, Qinghe) > group C (Wuyiling, Zhanhe, Liangzihe, Baihe, Chaihe, Caohekou, Bajiazi) >group D (Tongzigou, Dashitou, Wangqing, Helong, Yanshou, Dahailin, Xiaobeihu, Muling). The optimal base tree height growth model of the four groups was the Gompertz model, and the fitting accuracy of the model after the introduction of dummy variables (R²=0.9353) was higher than that of the base model (R²=0.9303), and the model prediction accuracy was also improved. The tree height growth curves of each provenance group conformed to the “S”-shaped rule of change. There were obvious differences among the groups, with the best performance of the provenances in group A. The growth of P. koraiensis from different provenances was different, and the tree height growth model with dummy variables of provenance groups could effectively improve the prediction accuracy of the model, reflect the differences in height growth of P. koraiensis of different provenances, which could provide the scientific basis for the selection and cultivation of P. koraiensis plantations.

In this paper, we collected the individual tree point cloud data in the plots of Larix olgensis plantations with different thinning intensities in Mengjiagang Forest Farm, applied the fractal analysis theory to extract box dimensions (D_b) on MATLAB platform, and characterized the structural complexity of L. olgensis. We assessed the effect of different thinning intensities and tree attributes on the structural complexity of L. olgensis. The results showed significant differences in L. olgensis D_b between control (CK: 1.68±0.07), low and medium intensity thinning (T₁, T₂, T₃: 1.74±0.07), and high intensity thinning (T₄: 1.81±0.06), which indicated that the thinning intensity increased tree structural complexity. For trunk attribute, the diameter at breast height and tree height was significantly positively correlated with D_b, while the height-to-diameter ratio was significantly negatively correlated with D_b. For canopy attribute, crown volume, surface area, projected area, and crown diameter was significantly positively correlated with D_b. Hegyi competition index was significantly negatively correlated with D_b in the control and low-moderate-intensity thinning treatments, but not significantly correlated with D_b in the high-intensity thinning treatment. It indicated that thinning influenced L. olgensis structural complexity, with trunk attribute and canopy attribute as the main drivers of L. olgensis structural complexity.

Warming drives material cycling in terrestrial ecosystems by affecting litter decomposition, as it can alter litter yield, quality and decomposer composition and activity. The effect of warming on the decomposition of mixed litter in arid and semi-arid zones remains unknown. We investigated the mass loss and nutrient release dynamics during 450 days of decomposition of Artemisia ordosica, Leymus secalinus, and their mixture in Mu Us Desert by open-top chambers and litter bags. The results showed interspecific differences in the responses to warming, in that warming promoted mass loss and N and P release from L. secalinus and inhibited mass loss and P but promoting N release from A. ordosica. Mixing of A. ordosica and L. secalinus litter inhibited decomposition. Warming enhanced the antagonistic effects of mixed decomposition. The total mass loss of mixed litter was decreased by 9%, and the release of N and P was decreased by 4.9% and 12.6%, respectively. The antagonistic effects of mixed litter mass loss and P release under the warming treatment gradually strengthened with time, with N release changing from a synergistic to an antagonistic effect at 150 d. The non-additive effects produced by the mixed decomposition of A. ordosica and L. secalinus litter were jointly regulated by temperature and time. Future research on mixed litter decomposition should consider the interaction between temperature and time.

To understand the adaptation of water use strategy of plant community to habitat heterogeneity, we measured the δD and δ¹⁸O values of xylem water of shrubs and potential water sources (soil water in different layers or groundwater) of Ammopiptanthus mongolicus communities on sand dune and Gobi from April to September in 2021 in the Ulan Buh Desert. Employing the MixSIAR model, we examined the seasonal dynamics of water source of each shrub by quantifying the contribution of different potential water sources. The results showed that A. mongolicus and Artemisia xerophytica on sand dune mainly used soil water of 10-25 cm in April and May after heavy rain in early spring, whereas Artemisia ordosica mainly used soil water of 10-200 cm. During the drought event within summer from June to August, A. mongolicus increasingly used soil water of 100-200 cm and groundwater, but A. xerophytica and A. ordosica increased the usage of 50-200 cm soil water. After the moderate rain in September, A. mongolicus evenly used soil water in all layers and groundwater, whereas two Artemisia shrubs preferred soil water of 10-50 cm. On Gobi, A. mongolicus and Nitraria sphaerocarpa evenly used soil water in all layers in April and May, mainly used 50-150 cm soil water from June to August and used 10-50 cm soil water in September. Convolvulus tragacanthoides mainly used soil water of 10-50 cm (from April to May), 25-150 cm (from June to August), and 10-25 cm (in September), separately. There were seasonal differences in water use of three shrubs on sand dune and Gobi A. mongolicus communities. During drought, A. mongolicus on sand dune could use deep soil water and groundwater, and that on Gobi relied only on deep soil water, which was more sensitive to rainfall.

Litter layer, serving as the “skin” of forest soil, plays a crucial role in conserving water resources and maintaining soil and water conservation. We analyzed the relationship of tree species richness, community weighted mean traits, and functional diversity with the standing mass, maximum water holding rate, and effective water sto-rage capacity of litters from various tree species including Liquidambar formosana, Mytilaria laosensis, Castanopsis sclerophylla, Castanopsis hystrix, Cunninghamia lanceolata, Pinus massoniana, Fokienia hodginsii, Taxus wallichiana and their combinations of mixed forests in subtropical region. The results showed that across various tree species combinations, the ranges of maximum water holding rate, standing litter mass and effective water storage capacity of undecomposed layer were 0-419%, 0-0.58 t·hm^-2, and 0-1.66 t·hm^-2, respectively. For the semi-decomposition layer, these values spanned in 0-375%, 0-6.14 t·hm^-2, and 0-16.03 t·hm^-2, respectively. Tree species richness and community weighted mean specific leaf area had significantly positive effects on standing mass of litter and effective water storage capacity, while community weighted mean leaf N content had significantly negative effect on standing mass of litter. The maximum water holding rate increased with the increases of functional diversity of specific leaf area and community weighted mean specific leaf area, decreased with the increase of community weighted mean leaf thickness. Results of structural equation model showed that tree species richness increased litter water holding capacity by increasing functional diversity of specific leaf area. The community weighted mean specific leaf area increased the water holding capacity of litter layer by increasing standing mass of litter and the maximum water holding rate. It is necessary to consider planting mixed forest with higher community weighted mean specific leaf area in the management of subtropical artificial forest, so as to improve the water holding capacity of litter layer.

In order to provide a guide for plant selection of ecological restoration at antimony (Sb) mining ecological damaged sites, species composition, importance value, niche, and interspecific associations of tree, shrub, and herb layers were examined at Sb mining site in Nandan City, Guangxi, China. The results showed that 23 vascular plant species were recorded at the Sb mining ecological damaged site, belonging to 22 genera and 13 families, primarily Gramineae, Cyperaceae, Fabaceae, and Asteraceae. The highest importance values for trees, shrubs, and herbs were observed in Rhus chinensis (56.7%), Coriaria nepalensis (56.3%), and Eremochloa ciliaris (44.0%), which were characterized by fairly large niche widths of 1.58, 1.32 and 1.57, respectively. The highest niche overlap values were found between R. chinensis and Triadica sebifera in the tree layer, and between Thysanolaena latifolia and Bidens pilosa in the herb layer, with the value of 0.68 and 0.99, respectively. Shrub layer exhibited a lower range of niche overlap (0.30-0.42), suggesting significant niche differentiation among different species. In the tree and shrub layers, most species showed insignificantly negative associations, the proportion was 83.3% and 66.7%, respectively, indicating that the plant community was not stable. Herb layer generally exhibited significantly positive correlations, with 52.4% of species pairs showing positive correlation, indicating weak resource competition among species. Overall, plant community at Sb mining ecological damaged site was unstable. In the process of ecological restoration, trees and shrubs that can adapt to the conditions and have positive associations should be prioritized in species selection, such as R. chinensis, C. lanceolata, C. nepalensis, and B. nivea. This will promote vegetation positive succession, rehabilitate the ecosystem and ensure sustainable development at Sb mining ecological damaged sites.

To understand the effects of nitrogen deposition on element cycling and nutrient limitation status in forest ecosystems, we examined the effects of nitrogen deposition on the stoichiometric characteristics of forest soil-microbial-extracellular enzymes in Pinus yunnanensis forest. We conducted a field experiment with control (CK, 0 g N·m^-2·a^-1), low nitrogen (LN, 10 g N·m^-2·a^-1), medium nitrogen (MN, 20 g N·m^-2·a^-1) and high nitrogen (HN, 25 g N·m^-2·a^-1) since 2019. We collected soil samples (0-5 cm, 5-10 cm and 10-20 cm) at September 2022, and measured the contents of soil organic, total nitrogen, total phosphorus, microbial biomass carbon, nitrogen and phosphorus (MBC, MBN, MBP) and the activities of C, N, and P acquisition enzymes. The results showed that nitrogen deposition significantly reduced soil organic content, C:N and C:P by 6.9%-29.8%, 7.6%-45.2% and 6.5%-28.6%, and increased soil total N content and N:P by 10.0%-45.0% and 19.0%-46.0%, respectively. Nitrogen addition did not affect soil total P content. Except for soil C:N and C:P, soil nutrient content and stoichiometric ratio were highest in 0-5 cm soil layer. MN and HN treatments significantly decreased MBN by 11.0%-12.7%. MBC, MBP, and their stoichiometry did not change significantly under nitrogen deposition. Soil microbial nutrient content in 0-5 cm soil layer was significantly higher than that in other soil layers. Nitrogen deposition significantly decreased the activities of cellobiose hydrolase and leucine aminopeptidase (decreased by 14.5%-16.2% and 48.7%-66.3%). HN treatment promoted β-1,4-glucosidase activity (increased by 68.0%), but inhibited soil enzyme stoichiometric carbon to nitrogen ratio and nitrogen to phosphorus ratio (decreased by 95.4% and 88.4%). LN and MN treatment promoted β-1,4-N-acetylglucosaminidase activity (increased by 68.3%-116.6%), but inhibited enzyme stoichiometric carbon to phosphorus ratio (decreased by 14.9%-29.4%). Alkaline phosphatase activity had no significant change. Soil enzyme activities were significantly decreased with increasing soil depth. Soil total N and total P and microbial nutrients were negatively correlated with vector angle (representing microbial nitrogen or phosphorus limitation), while vector length (representing microbial carbon limitation) was consistently significantly positively correlated with vector angle, suggesting the synergistic promotion between microbial carbon limitation and phosphorus limitation. Nitrogen deposition gradually shifted to phosphorus limitation while alleviating microbial nitrogen limitation in P. yunnanensis forest. In addition, microbial activities in this region was limited by C availability, and the relationship between microbial C and P limitation was proportional.

Exploring nutrient limitation in forest soil holds significant implications for forest tending and management. However, current research on nutrient limitation status of microorganisms in Robinia pseudoacacia plantations within the Loess Plateau remains insufficient. To investigate soil microbial nutrient limitation of R. pseu-doacacia plantations on the Loess Plateau, we selected R. pseudoacacia plantations with different afforestation time series (15, 25, 35, and 45 years) and a pile of barren slope cropland (control) in Yongshou County, Shaanxi Province as the research objects. We analyzed the contents of soil organic matter, total nitrogen, and total phosphorus, and the activities of β-1,4-glucosidase (BG), cellobiose hydrolase (CBH), leucine aminopeptidase (LAP), β-1,4-N-acetylglucoside (NAG) and phosphatase (AP). We analyzed the soil nutrient limitation by stoichiometry and enzyme metrology. The results showed a shift in soil pH from alkaline to acidic during vegetation restoration process, and that total phosphorus exhibited a gradual decrease over the course of 0 to 25 years. Soil orga-nic matter, total nitrogen and enzyme activities exhibited an increasing trend during the same time frame. However, between 25 and 45 years of age, soil total phosphorus, soil organic matter, total nitrogen, AP and LAP gradually declined while NAG, BG, and CBH initially increased and then decreased. Notably, the values of (BG+CBH)/(LAP+NAG), (BG+CBH)/AP and (LAP+NAG)/AP in R. pseudoacacia plantations were higher than the global average throughout the process of vegetation restoration. In the study area, the vector length was less than 1 and gradually increased, indicating that a progressive increase in microbial carbon limitation during the process of vegetation restoration. The vector angle exceeded 45° and exhibited an overall decreasing trend, suggesting that soil microorganisms were constrained by phosphorus (P) with a gradual deceleration of P limitation, without any nitrogen (N) limitation. The restoration of R. pseudoacacia plantation resulted in significant change in soil physical and chemical properties, while the time series of afforestation also influenced nutrient limitation of soil microorganisms.

Soil microorganisms play a crucial role as a link between vegetation and soil nutrient cycling. However, it is unclear how vegetation and soil influence microbial community during the ecological restoration process of the Mu Us Desert. Using phospholipid fatty acid (PLFA) markers and integrating shrub, herbaceous plants, and soil factors, we explored the characteristics and regulations of soil microbial community changes. In this study, we used and took the soil after 10, 30, 50, and 70 years of Caragana korshinskii sand-fixing forest restoration, with moving dunes as a control (0 year). The results showed that the ecological restoration effect index increased significantly with the increase of recovery years. The total PLFA contents in 0, 10, 30, 50, and 70 years were 47.75, 55.89, 63.53, 67.23, and 82.29 nmol·g^-1, respectively. With the increases of ecological restoration index, the biomass of fungi and bacteria, as well as the ratio of Gram-positive to Gram-negative bacteria, all showed significant increase, while the biomass of Gram-positive and Gram-negative bacterial communities, and the ratio of fungi to bacteria, demonstrated significant decrease. Shrub, herbaceous plants, and soil factors could explain 72.4% of the vari-ation of soil microbial community composition, with higher contribution of soil factors than vegetation factors. The total content of phospholipid fatty acids of soil microbial community in Mu Us Desert increased with the increases of restoration years. Soil water content, pH, total nitrogen, and soil organic carbon were the main driving factors affecting the characteristics of soil microbial community. With the increases of restoration years of C. korshinskii sand-fixation forests in the Mu Us Desert, there were significant changes in the structure of soil microbial communities, which were primarily driven by soil factors.

Exploring the physical fractions of organic carbon and influencing mechanisms in grassland, forest, and farmland soils in wind erosion area can provide scientific basis for carbon sequestration, land utilization, wind prevention measure making, and fertility restoration of sloping farmland in the region. We examined the differentiation of aggregate organic carbon and density fractionation organic carbon in 0-15 cm soil layer across grassland, forest, and sloping farmland with 350 m long and 5° slope gradient in the wind erosion area of Meilisi District, Qiqihar, Heilongjiang, as well as the sloping farmland in the downhill section, middle section, and uphill section with every 100 m apart from the bottom to the top. The results showed that soil aggregates >2 mm were all destroyed across grassland, forest, and farmland soils, while the percentage of aggregates <0.053 mm was significantly higher than that of other sizes. The percentage of various soil aggregates, organic carbon content from density fractionations, and the proportion of organic carbon in the heavy fraction aggregates in farmland were significantly lower than that in grassland and forest soils. Soil aggregates in the uphill section of farmland were completely destroyed, and organic carbon content in various size aggregates and density fractionations gradually decreased with increasing slope. The proportion of organic carbon in the heavy fraction aggregates decreased, but that in light fraction aggregates increased gradually. Soil organic carbon and available potassium were key factors affecting aggregate stability, aggregate organic carbon content, and organic carbon content in density fractionations, while the loss of organic carbon in aggregate led to a decrease in aggregate stability. In summary, compared with grassland and forest soils, the stability of soil aggregates, the aggregate organic carbon content, the organic carbon content in density fractionations, and the proportion of organic carbon in heavy fraction aggregates in farmland all decreased in the wind erosion area of Northeast China. With the increases of slope, the aggregate organic carbon content, the organic carbon content in density fractionations, and the proportion of organic carbon in the heavy fraction aggregates in sloping farmland all decreased. Planting trees, conserving and expanding grassland area, and increasing the application of organic materials in sloping farmland in wind erosion area are effective approaches to stabilize and increase carbon storage, improve soil structure, and enhance soil quality.

In northern China, soil temperature slowly rises in spring, often subjecting apple roots to sub-low-temperature stress. Sugar acts as both a nutrient and signaling molecule in roots in response to low-temperature stress. To explore the effects of exogenous sugars on the growth and nutrient absorption of Malus baccata Borkh., we analyzed growth parameters, photosynthetic characteristics of leaves, and mineral element content in different tissues of M. baccata seedlings under five treatments, including control (CK), sub-low root zone temperature (L), sub-low root zone temperature + sucrose (LS), sub-low root zone temperature + fructose (LF), and sub-low root zone temperature + glucose (LG). The results showed that compared to CK, plant height, root growth parameters, aboveground biomass, leaf photosynthesis, fluorescence parameters, chlorophyll content, and the contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in M. baccata seedlings were significantly decreased under the L treatment, and the content of Ca in roots was significantly increased. Compared to the L treatment without exogenous sugar, photosynthesis, functional parameters, chlorophyll content, and growth parameters increased to different degrees after exogenous sucrose, fructose, and glucose application. The N and P contents in roots were significantly increased. The N, P, and K contents significantly increased in stems while only the Ca content significantly increased in stems treated with sucrose. Leaf N, P, K, Ca, and Mg contents significantly increased after being treated with the three exogenous sugars. In conclusion, exogenous sugars can improve photosynthetic efficiency, promote mineral element absorption, and alleviate the inhibition of growth and development of M. baccata at sub-low root zone temperatures, and the effect of sucrose treatment was better than that of fructose and glucose treatments.

The mechanism for water-saving and high-yield of wide-range precision sowing technology remains unclear. We investigated the impact of wide-range precision sowing on the physiological characteristics of root system, water consumption, and grain yield of wheat ‘Jimai 22' during the growing seasons of 2017-2019. We set up two planting modes: wide precision sowing and conventional strip sowing, and three row spacings of 20 cm, 25 cm, and 30 cm under water-saving cultivation with supplemental irrigation to examine the effects of planting modes on root biomass and senescence characteristics of wheat, water utilization characteristics, interplant evaporation, grain yield, and water utilization efficiency. The results showed that the 25 cm treatment (K25) led to an increase in root weight density, root soluble protein content, and root activity by 7.2%-23.9%, 8.7%-25.1%, 10.7%-29.9%, and 7.3%-27.6%, 8.0%-38.5%, 15.2%-32.7%, respectively, compared to the other treatments. At the same row spacing, the wide-range precision sowing treatment showed a significantly higher soil water storage consumption and proportion to total water consumption compared to the conventional strip-tillage treatment. Additionally, irrigation and interplant evaporation were lower in the wide-range precision sowing treatment. The K25 treatment exhibited significantly higher water consumption and modal coefficient of water consumption from flowering to ripening than other treatments. Furthermore, it had significantly higher seed yield, water utilization efficiency, and irrigation utilization efficiency than the other treatments. We found that a 25 cm spacing in the lower rows and density of 180-270 plants·m^-2 was the water-saving and high-yielding planting pattern of wide-range precision sowing wheat in Huang-Huai-Hai region.

Graphene oxide (GO) is a novel nanomaterial being applied in different fields, but was less used as foliar fertilizer in agriculture. We conducted a pot experiment to analyze the effects of foliar spraying GO from 0 (control), 50 (T₁), 100 (T₂), 150 (T₃) and 200 mg·L^-1 (T₄) on the morphogenesis and carbon and nitrogen metabolism of kidney bean plants during the initiation of flowering to clarify the physiological effects of foliar spraying GO. The results showed that dry matter accumulation, the content of photosynthetic pigments, soluble sugars of T₁ to T₄ treatments, were significantly increased by 40.7%-43.4%, 10.4%-80.7%, 6.4%-9.1% in kidney bean plants compared with CK treatment, respectively. T₃ treatment performed the best. Meanwhile, the activities of sucrose phosphate synthase, acid converting enzyme and neutral converting enzyme of T₃ and T₄ treatments were increased by 25.7%-45.5%, 17.4%-28.6%, and 14.7%-20.1%, and the activities of nitrate reductase, glutamine synthetase, and glutamate synthetase of T₂ and T₃ treatments were increased by 8.1%-15.2%, 11.5%-25.0%, and 89.7%-93.1%, respectively. In conclusion, foliar spraying of appropriate GO in early flowering stage of kidney bean could increase the content of photosynthetic pigments, improve the level of photosynthetic carbon and nitrogen metabolism, and increase dry matter accumulation. T₃ treatment (150 mg·L^-1) was the most effective in this study.

Biological nitrogen fixation is the main source of nitrogen in ecosystems. The diversity of soil rhizobia and their effects on soybeans need further research. In this study, we collected soybean rhizosphere samples from eight sites in the black soil soybean planting area in Northeast China. A total of 94 strains of bacteria were isolated and identified using the 16S rRNA and symbiotic genes (nodC, nifH) analysis, of which 70 strains were identified as rhizobia belonging to the genus Bradyrhizobium. To further validate the application effects of rhizobia, we selec-ted seven representative indigenous rhizobia based on the results of phylogenetic analysis, and conducted laboratory experiments to determine their nodulation and the impacts on soybeans. The results showed that, compared to the control without rhizobial inoculation, all the seven indigenous rhizobia exhibited good promoting and nodulation abilities. Among them, strains H7-L22 and H34-L6 performed the best, with the former significantly increasing plant height by 25.7% and the latter increasing root nodule dry weight by 20.9% to 67.1% compared to other indi-genous rhizobia treatments. We tested these two efficient rhizobia strains as soybean rhizobial inoculants in field experiments. The promoting effect of mixed rhizobial inoculants was significantly better than single ones. Compared to the control without inoculation, soybean yield increased by 8.4% with the strain H7-L22 treatment and by 17.9% with the mixed inoculant treatment. Additionally, there was a significant increase in the number of four-seed pods in soybeans. In conclusion, the application of rhizobial inoculants can significantly increase soybean yield, thereby reducing dependence on nitrogen fertilizer during soybean production, improving soil health, and promoting green development in agriculture in the black soil region of Northeast China.

Atmospheric nitrogen (N) deposition could affect the structure and function of terrestrial plants. Non-N₂-fixing lichens are used to monitor atmospheric N deposition because they rely on the deposited inorganic N (i.e., ammonium and nitrate) as N sources. However, the uptake capacities of lichen on ammonium and nitrate remain unclear, which hinders the application of lichen N content to accurate bioindication of atmospheric N deposition levels. We investigated ammonium and nitrate uptake capacities of Cladonia rangiferina, which was treated with ammonium alone, nitrate alone, and ammonium and nitrate mixture solutions with different mixing ratios under light and dark conditions. The results showed that N uptake rates increased with ammonium and nitrate concentrations in solutions and generally followed the Michaelis-Menten saturation kinetics. Ammonium uptake of C. rangiferina showed higher values of affinity, and was more efficient than the nitrate uptake. Both rates and amounts of nitrate uptake decreased with increasing ratios of ammonium to nitrate in solutions, while ammonium uptake showed no substantial variations, indicating an inhibition of ammonium on nitrate uptake capability. The darkness significantly decreased the maximum uptake rate and efficiency of nitrate, but had much weaker effects on lichen ammonium uptake. These findings highlight the preference of lichen on ammonium as a key N uptake strategy. It is thus necessary to consider the main types of atmospheric inorganic N deposition when using lichens to monitor atmospheric N pollution levels and evaluate N deposition based on lichen ecophysiology.

The lower limit temperature in the crop water stress index (CWSI) model refers to the canopy temperature (T_c) or the canopy-air temperature differences (dT) under well-watered conditions, which has significant impacts on the accuracy of the model in quantifying plant water status. At present, the direct estimation of lower limit temperature based on data-driven method has been successfully used in crops, but its applicability has not been tes-ted in forest ecosystems. We collected continuously and synchronously T_c and meteorological data in a Quercus variabilis plantation at the southern foot of Taihang Mountain to evaluate the feasibility of multiple linear regression model and BP neural network model for estimating the lower limit temperature and the accuracy of the CWSI indicating water status of the plantation. The results showed that, in the forest ecosystem without irrigation conditions, the lower limit temperature could be obtained by setting soil moisture as saturation in the multiple linear regression mo-del and the BP neural network model with soil water content, wind speed, net radiation, vapor pressure deficit and air temperature as input parameters. Combining the lower limit temperature and the upper limit temperature determined by the theoretical equation to normalize the measured T_c and dT could realize the non-destructive, rapid, and automatic diagnosis of the water status of Q. variabilis plantation. Among them, the CWSI obtained by combining the lower limit temperature determined by the dT under well-watered condition calculated by the BP neural network model and the upper limit temperature was the most suitable for accurate monitoring water status of the plantation. The coefficient of determination, root mean square error, and index of agreement between the calculated CWSI and measured CWSI were 0.81, 0.08, and 0.90, respectively. This study could provide a reference method for efficient and accurate monitoring of forest ecosystem water status.

Investigating the wind speed flow field and aerodynamic characteristics of shelterbelts with different structural features is of significant importance for the rational arrangement of shelterbelts and the mitigation of wind-blown sand disasters. Considering five cross-sectional shapes of shelterbelts (rectangle, windward right-angle triangle, leeward right-angle triangle, isosceles triangle, and parabolic) and four layout forms (single shelterbelt, L-shaped network, U-shaped network, and rectangular network), we conducted computational fluid dynamics (CFD) simulations using the large eddy simulation (LES) turbulence model to understand mean wind speed flow field and turbulence structure of shelterbelts with different structural features, and investigated the effects of shelterbelt cross-sectional shapes and layout forms on windbreak indicators, such as protection distance and area. We considered tree canopies as porous media and conducted simulation with the ‘Tsujimatsu' shelterbelt in Japan with a total height (H) of 7 m, canopy height of 5.8 m, and a canopy base width of 2 m. The results showed that the average relative errors of mean wind speed and turbulent kinetic energy at different heights obtained by numerical simulations and field measurement were small, being 5.5% and 12%, respectively, indicating that the porous medium canopy model successfully reproduced the mean wind speed and turbulent kinetic energy in the leeward area of the shelterbelt. The rectangular cross-section shelterbelt, with the largest canopy volume, significantly obstructed airflow. The mean wind speed and turbulent kinetic energy showed a notable reduction in the leeward area near the shelterbelt, especially in the upper region (z≥0.5H, where z denoted the height), showing the largest protection range. The parabolic cross-section shelterbelt ranked second in terms of protection range, followed by shelterbelts with windward right-angle, leeward right-angle, and isosceles triangular cross-sections. In the downstream area where horizontal distance x≥10H, the mean wind speed and turbulent kinetic energy of shelterbelts with different cross-sectional shapes tended to be the same. Comparing the flow field structures of single shelterbelts and L-shaped, U-shaped, and rectangular networks, it revealed that the more shelterbelts oriented perpendicular to the incoming wind speed, the more pronounced the wind speed attenuation behind the canopy, a longer distance would be required for airflow to recover to the incoming wind speed. In contrast, the wind protection effect of shelterbelts paralleled to the wind direction was extremely limited, making the U-shaped and rectangular networks more effective in wind protection than single shelterbelts and L-shaped networks. The findings would provide references for the structural configuration and optimal layout of shelterbelt systems.

Clarifying vegetation changes and the driving factors can provide references for ecological restoration and sustainable social development. We analyzed vegetation distribution and trend changes in Henan Province and its basin zoning (Haihe River basin zoning, Yellow River basin zoning, Huaihe River basin zoning, Yangtze River basin zoning), with fractional vegetation cover data from 2000 to 2020 based on the Google Earth Engine platform, and by combining Theil-Sen Median trend analysis, Mann-Kendall test, and Hurst index. We also utilized factor detection and factor interaction to explore the individual and mutual influences of natural and anthropogenic factors on vegetation at different scales. The results showed that the fractional vegetation cover (FVC) in Henan Province exhibited a distribution pattern of higher coverage in the south and lower in the north during the study period, predominantly characterized by moderate to high vegetation coverage. The Yangtze River basin zoning had the highest coverage. FVC in Henan Province and its zoning exhibited a consistent pattern of fluctuating upward trends, with all areas showing significant improvement. Particularly, the Yangtze River basin zoning had the largest area of improvement. According to the Hurst index, apart from the possibility of continued improvement in the Huaihe River basin zoning, other zoning would be likely to shift from improvement to degradation in the future. Vegetation changes in Henan Province and its zoning were the result of combined effects of anthropogenic and natural factors, with the influence of these factors changing over time and the dominant factors varying by region. Anthropogenic factors such as land use/cover type and nighttime lighting had a stronger impact on vegetation than natural factors like elevation, slope, and annual mean low temperature. The interaction between factors, particularly between anthropogenic and natural factors, exhibited a nonlinear enhancing pattern.

Rosa multiflora, originated from East Asia, is one of the original ancestors of modern roses. It is also an important genetic resource and rootstock for rose cultivation. Due to its high resistance and vigorous growth, R. multiflora has become an invasive species in some introduction sites, such as North America. To explore the correlation between the suitable habitat of R. multiflora and climate change, we predicted its potential geographic distribution with an optimized MaxEnt model based on 1246 distribution records and nine bioclimatic variables. The results showed that the mean temperature of the coldest quarter, minimum temperature of the coldest month, precipitation of the warmest quarter, and isothermality were significant bioclimatic variables affecting the potential geographic distribution of R. multiflora. Under current climate conditions, R. multiflora naturally distributed in the plains and hilly areas to the east and south of the Loess Plateau. The distribution pattern in the mid-holocene was similar to its current distribution, but the highly suitable distribution area was in the south of North China Plain, the Sichuan Basin, and parts of the Middle-Lower Yangtze Plain. During the last interglacial, the suitable areas generally contrac-ted southward, while the highly suitable areas significantly expanded and mainly located in the Sichuan Basin, the Middle-Lower Yangtze Plains, the Yunnan-Guizhou Plateau, and the Southeast Hills. Beyond its natural distribution in East Asia, R. multiflora had been introduced and spread to most parts of Europe and the central and eastern United States. The distribution area of R. multiflora would expand under three warming scenarios of different shared socioeconomic pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5) during 2041-2060 and 2081-2100. Its average distribution center (centroid) would shift towards higher latitude, indicating that the distribution of R. multiflora was closely related to climate change and that global warming might lead to an expansion of its distribution area. These results would improve our understanding of the ecological adaptability of R. multiflora, facilitate the predicting of its future distribution, and provide a theoretical basis for monitoring and early warning measures following its introduction.

Real-time assessment of ecological environment quality in arid and semi-arid regions is crucial for the sustainable development of ecological environments in China. In this study, we constructed a topsoil remote sensing ecological index (TRSEI) by coupling five indicators, greenness, wetness, dryness, topsoil grain size, and heat, with the Google Earth Engine (GEE). With the index, we evaluated the ecological environment quality of Wuchuan County from 1990 to 2020, and examined the spatio-temporal variations of ecological environment quality and its driving factors by using univariate linear regression, multiple regression residual analysis, and Hurst index. Results showed that the first principal component of the TRSEI in the study area contributed over 70%, with a mean eigenvalue of 0.148, indicating the effective integration of various ecological indicators by TRSEI. The topsoil grain size index was essential for the assessment of ecological environment quality in arid and semi-arid regions. From 1990 to 2020, the fluctuation range of TRSEI in the study area was between 0.289 and 0.458, showing an overall slight deterioration trend. The ecological environment quality of cropland and de-farming region had improved, with the improved area accounting for 47.9% of the total area. The grassland, barren land, and construction land areas had deteriorated, with the deteriorated area accounting for 52.1% of the total area. In the future, 36.9% of the regions would experience continuous improvement in ecological environment quality, while 41.4% might continue to dete-riorate. Human activities were the primary driving factor for the changes in ecological environment quality in arid and semi-arid regions, accounting for 88.6% of the total area. Climate change also had a significant impact, accounting for 11.4% of the total area. The TRSEI could effectively assess the ecological environment quality of arid and semi-arid regions, providing a scientific basis for ecological conservation and construction in these areas.

Ecological security pattern is an important spatial way to maintain ecological processes and ensure the stability of ecosystem functions. As the implementation of landscape planning and decision-making, it is critically needed to consider the consistency of differentiated methods and their spatial outputs in the construction of ecological security patterns and the matching and applicability of research objects. From the perspective of integration, we combined the regional topography and landscape characteristics, integrated the morphological spatial pattern analysis and the importance evaluation results of ecosystem services to identify the ecological source, and constructed the ecological security pattern of the Ansai District of Yan'an City, the main implementation area of the Grain-for-Green Project on the Loess Plateau. The results showed that the structural and functional construction methods had low consistency in the identification of spatial protection priority. The integration-oriented method could complement each other and achieve the dual goals of structural connectivity and functional improvement. There were 202 ecological sources in the study area, with a total area of 391.58 km², accounting for 13.3% of the total area of the study area. There were 110 ecological corridors in the study area, with a total length of 599 km, which were mainly distributed around the river channel, showing a distribution pattern of ‘short and narrow dense in the north and south, long and wide in the middle'. The structure-function integration method provides new insights for ecological restoration planning of land space and promotes the research of landscape pattern, process and service.

Clarifying the matching degree and the trade-offs and synergies between supply and demand of ecosystem services is of significance for scientific division of management zoning and sustainable urban development. We calculated the supply and demand of ecosystem services at the sub-district (town) scale of Taiyuan based on multi-source data, explored the coldspots and hotspots area of the supply-demand ratio and the trade-offs and synergies of six ecosystem services using the Getis-Ord Gi^* tool and correlation analysis, and proposed strategies based on the regional characteristics of natural-resource and socio-economy. Results showed the distribution of the supply and demand of ecosystem services had a spatial heterogeneity. In terms of supply, the area with high supply of carbon storage, air purification, thermal environment regulation and recreation service were located in the east and west parts, that of soil conservation in the west and water yield in the south part. In terms of demand, the demand distribution of carbon storage, thermal environment regulation, water yield and recreation service were characterized by high in the central and east-south area, and low in the periphery, and high demand of air purification in south and north parts, soil conservation in west part. There were substantial mismatches between the demand and supply of ecosystem services. The risk levels of the supply and demand of six ecosystem services showed a decreasing pattern from the Fenhe River to the eastern and western mountains. There were trade-offs between water yield and other five ecosystem services in their supply, while air purification and soil conservation had trade-offs with other four ecosystem services in demand. Based on the regional ecological management framework, we divided the study area into three primary zones and eight secondary zones, and proposed differentiated ecological management strategies to provide theoretical support for ecological zoning. The results could provide a basis for balancing the relationship of supply and demand of ecosystem services and promoting the sustainable development of the city.

Understanding the responses of ecosystem service trade-offs and synergies in metropolitan areas to the multidimensional expansion of urban space is of great significance for the optimization of regional land spatial pattern and high-quality development. With the Guangfo Metropolitan Area as research region, we used land use data and natural ecological environment data from 2000 to 2020 to measure the expansion characteristics of urban space in the dimensions of scale, distribution, and morphology by using the landscape pattern indices. We further calculated four main ecosystem services: urban cooling, habitat quality, recreation, and water conservation by the InVEST model, quantified the trade-off and synergistic relationship of multiple ecosystem services by the coupling coordination degree model, and explored its response to multidimensional urban spatial expansion by using the multi-scale geographically weighted regression model. The results showed that urban land use scale in the Guangfo Metropolitan Area continued to increase from 2000 to 2020, with an accelerated growth rate from 2010 to 2020. The ave-rage patch area of urban land in the central area and the urban land of small patches in the northeast increased, evolving from a “dual-center” structure to a “single-center” one. The distance between urban land patches in the Guangfo Metropolitan Area was relatively small, indicating a compact distribution of urban land. The distance between newly developed urban land patches was also small, but had gradually increased in recent years. The patch shape of urban land was relatively regular and less complex, but the complexity of the newly added urban land gra-dually increased. The ecosystem service trade-offs and synergies in the Guangfo Metropolitan Area had undergone significant changes, with a decrease in synergies and an increase in trade-off, and extreme trade-offs had gradually become dominant. The response of ecosystem services synergies to changes in urban land use scale was the most intense and had spatial heterogeneity, while the response to the change of distribution and morphological characte-ristics of urban land showed periodic differences.

Identifying and quantifying water nitrate pollution is crucial for managing aquatic environment of a bay. Dongshan Bay, a significant semi-enclosed bay in the southeastern coastal area of Fujian Province, features mangrove and coral reef ecosystems at its estuary and bay mouth, respectively. Dongshan Bay is impacted by human activities such as mariculture. We quantified and analyzed nitrate pollution status in the surface waters of Dongshan Bay by measuring physicochemical parameters, stable isotopes (δ¹⁵N-NO₃^-, δ¹⁸O-NO₃^- and δ¹⁵N-NH₄⁺) of the surface waters, and using statistical methods including the MixSIAR isotope mixing model. The results showed that the concentrations of chlorophyll a and dissolved inorganic nitrogen in the surface waters exhibited a noticeable gradient change, decreasing from the estuary of the Zhangjiang River to the mouth of Dongshan Bay. The maximum concentrations of chlorophyll a, NH₄⁺, NO₃^- and NO₂^- were 45.2 μg·L^-1, 52.67 μmol·L^-1, 379.2 μmol·L^-1 and 3.93 μmol·L^-1, respectively. The nitrogen and oxygen isotope values of NH₄⁺ and NO₃^- in the surface waters showed significant spatial variations. According to the MixSIAR model results, nitrogen sources in the surface waters of Dongshan Bay were mainly freshwater inputs of the Zhangjiang River estuary, aquaculture wastewater, and groundwater. The freshwater input from the Zhangjiang River estuary contributed the most (25.2%), while aquaculture wastewater, groundwater and urban sewage accounted for 24.6%, 19.0%, and 15.1%, respectively. It is evident that freshwater input from the Zhangjiang River estuary is the primary source of nitrate in the surface waters of Dongshan Bay.

Rodent-infested bald spots are crucial indicators of rodent infestation in grasslands. Leveraging Unmanned Aerial Vehicle (UAV) remote sensing technology for discerning detrimental bald spots among plateau pikas has significant implications for assessing associated ecological hazards. Based on UAV-visible light imagery, we classified and recognized the characteristics of plateau pika habitats with five supervised classification algorithms, i.e., minimum distance classification (MinD), maximum likelihood classification (ML), support vector machine classification (SVM), Mahalanobis distance classification (MD), and neural network classification (NN) . The accuracy of the five methods was evaluated using a confusion matrix. Results showed that NN and SVM exhibited superior performance than other methods in identifying and classifying features indicative of plateau pika habitats. The mapping accuracy of NN for grassland and bald spots was 98.1% and 98.5%, respectively, with corresponding user accuracy was 98.8% and 97.7%. The overall model accuracy was 98.3%, with a Kappa coefficient of 0.97, reflecting minimal misclassification and omission errors. Through practical verification, NN exhibited good stability. In conclusion, the neural network method was suitable for identifying rodent-damaged bald spots within alpine meadows.

The dynamics of soil arthropod communities in annual monoculture grasslands is still unclear, which restricts the understanding of the degradation mechanism of cultivated grasslands. We cultivated two annual gramineae species, Lolium multiflorum and Avena sativa, separately in Hongyuan County, located on the eastern edge of the Qinghai-Tibet Plateau, in April 2019. We investigated soil arthropods, plant communities and soil properties in the cultivated grasslands and natural grassland in the late September every year from 2019 to 2022. The results showed that: 1) The taxonomic composition of soil arthropod communities differed significantly among three grasslands and sampling years. 2) There was no significant difference in the density, taxonomic richness, Shannon index and evenness index of soil arthropod communities among three grasslands. 3) The density of soil arthropod communities significantly fluctuated across years in three grasslands, and the taxonomic richness and Shannon index decreased significantly in the L. multiflorum and A. sativa grasslands, with the evenness index declining significantly only in the fourth year. The Shannon index fluctuated significantly and the evenness index varied little in natural grassland. 4) The above- and below-ground biomass, the contents of soil total P, total K and available N were the main factors influencing the taxonomic composition, density and diversity indices of soil arthropod communities. The results suggested that the cultivation of annual gramineae grasslands have significant effects on taxonomic composition, but not on density and diversity of soil arthropod communities, and those variables change significantly across different years.

Pollination is one of the important ecosystem services related to sustainable development of human society. However, the population diversity and abundance of wild bees, important pollinators, have been significantly reduced by climate change, agricultural intensification, and landscape transformation. Re-establishment of pollinator habitat by planting nectar-producing plants is an important way to maintain pollination service. In this study, we investigated the status of wild bees and the traits of flowering plants in 22 apple orchards during flowering stage in Changping District, Beijing in 2019. We analyzed the response of wild bee diversity to the flowering plant richness, flower color richness, inflorescence type richness, flowering plant coverage, herbaceous layer coverage and different flower color coverage in apple orchards, aiming to provide guidance for the selection of nectar-producing plants to establish the habitat of wild bees. A total of 3517 wild bees were captured during the apple flowering season, representing 49 species, 13 genera, and 5 families. We identified 21 flowering plants species that shared a similar flo-wering period with apple, exhibiting a range of 5 colors and 9 inflorescence types. The Shannon diversity index, evenness index, and social bee richness of wild bee community were positively correlated with flowering plant richness. The total wild bee community richness, social bee richness, underground nesting bee richness were positively correlated with the richness of flowering plant color, but Halictidae bee abundance was negatively correlated with the richness of flowering plant color. The Shannon diversity index and evenness index of wild bee community were positively correlated with the richness of inflorescence types. Megachilidae bee richness was negative correlated with the white flower coverage. Megachilidae bee richness, social bee abundance, and ground nesting bee richness were positively correlated with the purple flower coverage. There was no significant correlation between wild bees and flowering plant richness, flower color richness, inflorescence type richness, flowering plant coverage, herbaceous layer coverage and different flower color coverage in other communities of different families, lifestyles and nesting types. Maintaining diverse ground flowering plants with various traits in orchards is important to improve the diversity of wild bees. In particular, increasing the coverage of purple flower during apple flowering period is helpful to promote the diversity of Megachilidae bee, social bees, and ground nesting bees.

We assessed the diversity, composition, and distribution of bird species in patches of semi-humid evergreen broad-leaved forest by selecting eight natural forest communities in the central Yunnan Plateau, which is a representative distribution area of semi-humid broad-leaved evergreen forest. Field observations were conducted from April to August 2023 by the sample line and sample point method, and eight survey routes of 3-4 km in length were established. The results showed that 1) A total of 1286 birds were recorded, belonging to 102 species in 7 orders and 30 families. The three most abundant families were Muscicapidae (14 species), Leiothrichidae (9 species), and Phylloscopidae (7 species); 2) Species of Oriental origin, Palaearctic origin, and widespread species accounted for 81.4%, 4.9%, and 13.7% of observations, respectively; 3) The average number of bird species surveyed in forest patches was 32.0±3.5; the Shannon index of birds was lower in secondary, semi-humid evergreen broad-leaved forests (1.536±0.110) than in primary forest communities (2.037±0.100); 4) Species composition exhibited considerable variation between patches, with the presence of dominant and common species, and the difference in rare species; 5) Considering the ecological groups of birds based on diet, invertebrate-eating and omnivorous birds, herbivorous birds, and carnivorous birds accounted for 84.3%, 11.8%, and 3.9%, respectively. The coexistence of birds with similar diets was maintained by diluting interspecific competition, mainly through partitioning of the vertical feeding space. For the conservation of bird species diversity and rare species, all patches of native semi-humid evergreenbroad-leaved forest are of conservation value.

Studying the stoichiometric characteristics of soil nutrients aids in evaluating soil quality and deciphering the coupling of soil nutrients. The influence of migratory bird activities on the dynamics of wetland soil nutrients and their stoichiometric remains unclear. We classified the central, peripheral and adjacent natural grassy areas as severe, mild, and no bird activity (control), respectively, in Donghu Carex meadow, a representative migratory bird habitat in Poyang Lake, based on flock characteristics and initial surveys. We analyzed the contents and stoichio-metry of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) across soil depths of 0-100 cm under different intensities of migratory bird activities. The results showed that the activities of migratory birds significantly impacted nutrient levels exclusively within 0-30 cm soil. Mild activities markedly enhanced SOC and TN across 0-30 cm soil, while both mild and severe activities significantly raised TP within the same depth. For the 0-100 cm soil profiles, soil C/N ratios were 10.0, 10.8, and 9.9, C/P ratios were 23.5, 30.0, and 22.7, and N/P ratios were 2.3, 2.7, and 2.3 under no, mild, and severe bird activities, respectively. Further, mild activities of migratory birds significantly increased soil C/N, C/P and N/P ratios only within the 0-30 cm depth, while the stoichiometric ratios of all soil layer had no significant difference under severe bird activity. Soil stoichiometric ratios strongly correlated with physicochemical properties. SOC, TN, and TP primarily mediated the effects of migratory bird activity on soil carbon, nitrogen, and phosphorus stoichiometric ratios in Poyang Lake wetland. In conclusion, the influence of migratory bird activity on the stoichiometric ratios of soil carbon, nitrogen, and phosphorus in Poyang Lake wetland exhibited depth threshold (approximately 30 cm), aligning with the “Intermediate Distur-bance Hypothesis”. These findings could provide a new perspective for the protection of wetlands and migratory birds.

Ecosystem regime shifts refer to the drastically changes of an ecosystem from one state to another after suffering disturbances that exceed the thresholds. Although land desertification and grassland degradation, which are common in the cold and arid regions, are gradual processes, sudden changes can also occur when the duration or intensity of disturbances exceed the thresholds. Therefore, the study of ecosystem regime shifts is of great significance to the management of ecosystems in cold and arid regions. In this review, we summarized the evolution of ecosystem regime shift theory and early warning signals, and analyzed the problems of land desertification and grassland degradation in cold and arid regions, as well as potential responses of ecosystems to different stresses. We further put forward research frameworks for the evolution and mutation characteristics of the rain-fed artificial sand fixation system and alpine meadows. The future research needed to be strengthened in identifying the key drivers of ecosystem regime shifts at different stages, determining the corresponding thresholds, emphasizing the mechanism of water-limited mutation induced by extreme climatic events and its early warning, and promoting the application of regime shift research to ecosystem management in arid and arid regions.

Wildlife resources are strategic resources of a country, and the investigation of which is a key task for effective management in protection and utilization. Since the 1990s, two national surveys of terrestrial wildlife resources have been carried out in China, and the situation of wildlife resources has been known to a certain extent. Due to the complexity and difficulty of national wildlife survey, we are still not able to grasp the background and dynamics of wildlife resources as a whole promptly and effectively. The results and effectiveness of wildlife resources investigation will directly affect the decision-making related in wildlife protection. According to Law of the People's Republic of China on the Protection of Wildlife and Regulations of the People's Republic of China for the Implementation of the Protection of Terrestrial Wildlife, it is imperative to carry out the third national survey of terrestrial wildlife resources, and to be integrated with the national strategy of ecological civilization construction. The aims of this review were to summarize the earlier experiences in time, to further improve the investigation scheme and technical methods, to serve the third national survey of terrestrial wildlife resources, in addition to obtain more comprehensive and reliable data of wildlife resources, grasp the development trend of domestic wildlife resources, and provide more effective supports for the wildlife conservation in China.

Plants could effectively adsorb and remove particulate matter from the air, while could be suffered from the adverse effects. Therefore, exploring the interaction between plants and atmospheric particulate matter is crucial for profound understanding of ecological balance, microenvironmental climate, and environmental quality improvement. Few systematic literature have elaborated the adsorption and response mechanisms of atmospheric particulate matter by plants. We summarized the causes and composition of atmospheric particulate matter, as well as the adsorption methods and factors of plants on atmospheric particulate matter. Moreover, we elaborated the impact of atmospheric particulate matter stress on phenotypic and physiological characteristics, as well as molecular mechanisms. For the future researches, we proposed 1) to select plant species with strong adaptability and high dust retention capacity. Subsequently, there should be a universal green dust retention plan on account of comprehensive factors such as plant community structure, street morphology, and planting space; 2) to extend the research from urban areas to agricultural and pastoral areas, with a systematic analysis of the comprehensive dust retention capacity of communities with different plant configuration; 3) to effectively combine the dust retention capacity of plants with their own resistance. Subsequently, we should explore the physiological and molecular mechanisms of plants responding to atmospheric particulate matter stress and establish a comprehensive evaluation system and criteria; 4) to develop in situ labeling detection technology, which would be a valuable tool for accurately tracing and quanti-fying the dynamics of atmospheric particulate matter within plant at the cellular level.